Evaluation Indices of an Asphalt-Mixture Digital Specimen Based on the Discrete-Element Method

摘要

To evaluate the generation method of a digital asphalt-mixture specimen based on the discrete-element method, an algorithm for generating three-dimensional coarse aggregates is presented in this study. The simulation result shows that this algorithm can reflect the actual geometry (e.g., shape, size, fracture surface, and angularity) of aggregate particles. The digital three-dimensional specimen generated using this algorithm can model the three-phase system of coarse aggregates, air voids, and asphalt mastic for asphalt mixtures well. To estimate the distribution of coarse aggregates, both in the digital specimen and real asphalt mixture, the position and quantity of the coarse aggregates within a two-dimensional section of the asphalt mixture were adopted as evaluation indices. The results showed that the digital asphalt-mixture specimen was in good agreement with the real asphalt mixture, and the evaluation indices could be used to quantitatively analyze whether the digital specimen could reflect the real asphalt mixture. The proposed approach based on the discrete-element method can be used as a supplemental tool to evaluate the uniformity of asphalt mixtures for micromechanical analysis.